Purple shampoo is a special hair care product designed to neutralize unwanted yellow or brassy tones in blonde, silver, or gray hair. It contains purple pigments that counteract warm tones, helping to maintain a cooler, more vibrant hair color. Typically used once or twice a week, purple shampoo is applied like regular shampoo and left on the hair for a few minutes before rinsing. It is popular among those who dye their hair blonde or have highlights, as it helps to extend the life of the color and keep hair looking fresh and bright.